Another of the Chibok schoolgirls kidnapped by Boko Haram has been rescued by Nigerian soldiers.

She was discovered wandering in the bush near the Islamic extremist group's forest stronghold, army spokesman Col. Sani Kukasheka Usman said.

Some 276 young girls were abducted by the group in 2014, shocking the world and sparking a huge campaign with the slogan "Bring Back Our Girls".

Within weeks 57 of the schoolgirls managed to flee.

One of the girls escaped in May 2016 and in October the government negotiated the release of 21 more.

Another girl was freed in November in an attack on an extremist camp in the Sambisa Forest.

More than 200 of the girls remain missing, though several reportedly have died from things like malaria and snake bites.